1. Field of the Invention
The present invention relates to a rebound exerciser, and more particularly, to a portable rebound exerciser which is constructed to be readily compacted, and easily transported and stored, without removal of the mat from the frame, and to readily adjust mat tension for individuals of varying weight.
2. Description of the Prior Art.
Rebound exercisers generally consist of a mat of flexible, resilient webbing which is secured to a tubular frame by means of a plurality of coil springs. The frame is positioned a relatively short distance off the ground, for example, 7-8 inches, by a plurality of legs which are attached thereto. As fully assembled, an individual can perform a variety of aerobic exercises by, for example, flexing, jumping stretching, jogging, twisting, dancing, hopping, and kicking, while positioning some portion of his (her) body on the mat. Such exercises improve blood and lymph circulation and tone muscles due in part to increased cellular and muscular stress imparted by increased gravitational force encountered during such exercises. A variety of rebound exercisers are currently available on the market. However, none of these exercisers has proved to be totally acceptable.
One problem plaguing all prior art rebound exercisers is that due to the size thereof, the exercisers are not readily manipulated for tansportation and/or storage. A proposed prior art solution is to break down the exerciser into component parts, thus reducing the overall bulk of the exerciser. However, as reassembly of the exerciser, especialy the spring attachment to the mat and frame often involves the use of a separate tool and is difficult and time consuming, e.g., 11/2 hours, this prior art approach to portability has not proved altogether viable. Further, once broken down, these prior art exercisers still do not meet the size requirements for shipping by United Parcel Service, and thus, shipping thereof is significantly more expensive.
It has also been proposed to equip prior art rebound exercisers with removable legs to increase compaction thereof. To date the prior art approach has been to secure a threaded female coupling at various points to the underside of the frame and thread the exterior of one end of each leg, as disclosed in U.S. Pat. No. 3,892,403 to Green. Each leg can then be coupled with the female coupling for use and uncoupled therefrom for transportation and/or storage as desired. However, as the mated threads are the sole point of support for the frame, these threads become damaged upon being subjected to repeated jarring during use of the exerciser therby increasing the difficulty of removing the legs and decreasing the stability of the overall frame.
Still another problem encountered in use of prior art exercisers is that the tension of the mat may be excessive or insufficient to suit the needs of the individual exercising. For example, a relatively lightweight individual may find a tight mat (i.e., a mat having a tension which is excessive in relationship to his weight) produces little or no spring during exercising and is uncomfortable and jarring. Prolonged exercising on this mat can result in injuries to the joints and internal system of an individual. Equally exemplary, a relatively heavy individual may find the same mat too loose (i.e., insufficient mat tension for his weight) resulting in minimal benefit from exercising since insignificant acceleration and deceleration (which increases the gravitational force on the body) is achieved. All of the prior art exercisers fail to provide for adjustment of spring, and thus, mat tension for varying individual weights.
Thus, a need exists for a rebound exerciser which can be readily compacted without total disassembly thereof for transportation and/or storage, which can be inexpensively shipped, and which provides for adjustment of spring and mat tension so as to accomodate individuals of varying weight.